What entities are likely to be found in a relational catalog?

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Request for Question Clarification by maniac-ga on 26 Jul 2003 15:46 PDT

Hello Helloworld,

First, the relational catalog is the description of the data base and
its contents. Generally this information is stored in the data base a
another table - perhaps with a reserved name and is not directly
updated by user applications. A synonym for relational catalog is
"system catalog" or sometimes called "data dictionary". Examples of
entities (and a few of their attributes) include:

 - Databases (name, filename / location)
 - Tables (name, type, format, size, creator)
 - Logs (name, status, filename / location)
 - Variables (name, type, value)
 - Columns (name, type, format, size)
 - Constraints (name, formula)
 - Users (name, rights)

In this way, the relational database system can allow user
applications to adjust its processing based on the data used by the
RDBMS to manage the information. There are usually a set of relations
that go with these entities as well - for example, a relation
indicating the columns that belong in a table. In the references below
- I have tried to supply a few concrete examples from INGRES, MySQL,
and Oracle.

For reference / more information check out
  http://www.indianflair.com/articles/rdbms.htm
  "Codd's 12 rules" of RDBMS

  http://bpaosf.bpa.arizona.edu/~wei/eval_report.doc
  A word document describing MySQL, includes a list of items recorded
in the system catalog

  http://www.cs.usm.edu/~bisland/classstuff/csc411/Database.ppt
  A presentation that outlines basic data base concepts including the
relational (system) catalog.

  http://www.cs.umu.se/kurser/TDBC86/Latest/Slides/16_OH_catalog.pdf
  A good explanation of a system catalog and the kinds of data stored
in it.

  http://bpaosf.bpa.arizona.edu/~fcurrim/mis331/project/systab.html
  A more specific example of system tables for Oracle.

  http://bpaosf.bpa.arizona.edu/~fcurrim/mis331/project/oracle.html
  A tutorial for Oracle, section 17 has a series of SELECT commands to
extract data from the system tables. Note that the names of the views
do not necessarily map directly to entities in the relational catalog.

  http://www.cs.mu.oz.au/~yuan/Ingres/us_38622.html
  In this case specifics for the Ingres "User's file".
  http://www.cs.mu.oz.au/~yuan/Ingres/us_25156.html
  Specifics for system files that are not clearly described in the
current Ingres documentation.

  http://database.sarang.net/database/ingres/INGRES.ppt
  "The Design and Implementation of INGRES" (starting at page 16 -
describes the system catalog)

Search phrases used include
  relational database catalog entities
  "relational catalog" contents
  "relational catalog" entities
  +oracle "system catalog"
  +ingres "system catalog"
  codd's 12 rules

  --Maniac

Hello Helloworld,

Oops. The material I already posted is my answer. Please review that
and if there are any further questions on this topic, please use a
request for clarification.

  --Maniac